The present invention relates to a relay connector for electrically connecting a core conductor of a coaxial connector to a terminal electrode which is provided on a surface of a board, and at the same time, electrically connecting a shell ground (GND) of the coaxial connector to a GND electrode which is provided on a back face of the board, for the purpose of inspecting the board.
In designing and producing a high frequency circuit board or the like, it is necessary to evaluate its performance in the process of designing. For this purpose, a core conductor of a coaxial connector is electrically connected to a terminal electrode which is provided at an end part of a surface of a board, and at the same time, a shell GND of the coaxial connector is electrically connected to a GND electrode which is provided at an end part of a back surface of the board, thereby to conduct evaluation of the performance based on the high frequency signal obtained from the terminal electrode. In case where soldering is employed in electrically connecting the core conductor of the coaxial connector to the terminal electrode and in electrically connecting the shell GND of the coaxial connector to the GND electrode, such soldering process is troublesome. Moreover, a process for removing the coaxial connector which has been soldered and fixed to the board is also troublesome. Therefore, a related-art relay connector in which the coaxial connector can be mounted to the board without soldering has been proposed (refer to JP-A-2008-171801).
The related-art relay connector disclosed in JP-A-2008-171801 will be briefly described referring to FIGS. 12A to 14. FIGS. 12A, 12B and 12C are views showing an outer appearance of the related-art relay connector, FIG. 12A is a side view, FIG. 12B is a plan view, and FIG. 12C is a front view. FIG. 13 is a sectional view taken along a line A-A in FIG. 12B. FIG. 14 is an exploded perspective view of the relay connector as shown in FIGS. 12A to 12C. In the related-art relay connector as shown in FIGS. 12A to 14, a main block 20 formed of conductive material is provided with a through hole 20a, and a dielectric member 22b projected from a shell GND 22a of a coaxial connector (SMA type connector, for example) 22 is inserted into the through hole 20a from a backside surface, and the shell GND 22a is fixed to the backside surface with screws, and electrically connected thereto. Further, a core conductor 22c peeled out of the dielectric member 22b is projected from a front surface of the main block 20. In this state, an end surface of the dielectric member 22b is substantially flush with the front surface of the main block 20 or retracted from the front surface. An axial direction of the core conductor 22c is perpendicular to the front surface of the main block 20. Guide pins 24, 24 are uprightly provided on the main block 20 in parallel with the front surface. A ground (GND) block 26 formed of conductive material is formed with guide holes 26a, 26a into which the guide pins 24, 24 are inserted. In this structure, by inserting and withdrawing the guide pins 24, 24 into and from the guide holes 26a, 26a, the GND block 26 can relatively move with respect to the main block 20 in slidably contact, in a linear direction parallel to the front surface thereof. Further, the GND block 26 is provided with a board rest part 26b so as to be opposed to the core conductor 22c in such a manner that the board rest part 26b can relatively move in a direction of approaching and separating with respect to the core conductor 22c. 
Further, an operating member 30 is provided so as to relatively move in a direction of approaching and separating with respect to the main block 20 in a determined range, by inserting moving range limiting screws 32, 32 into moving range limiting through holes 30a, 30a which are formed in a vertical direction passing through the operating member 30, in an axial direction so as to move in a determined range, and screwing distal ends of the screws into the main block 20 at an opposite side to a side where the GND block 26 is provided, with respect to the core conductor 22c. The direction of the GND block 26 approaching and separating with respect to the core conductor 22c, and the direction of the operating member 30 approaching and separating with respect to the main block 20 are parallel to each other. In addition, elastic springs 34, 34 are provided between the operating member 30 and the main block 20 in a contracted state, and the operating member 30 is elastically urged so as to be separated from the main block 20. Further, the operating member 30 and the GND block 26 are coupled by means of coupling members 38, 38 with coupling pins 36, 36. The coupling members 38, 38 move the GND block 26 so as to approach and separate with respect to the core conductor 22c, following the movement of the operating member 30 in the approaching and separating direction. Still further, a leaf spring 40 having conductivity is fixed to the GND block 26 with small screws, and the GND block 26 is slidably disposed so as to be brought into elastic contact with the main block 20 which relatively moves in the approaching and separating direction, and electrically connected thereto. A lateral width W of the related-art relay connector is set to be 12.7 mm, for example, that is, the same size as a lateral width of the shell GND 22a of the coaxial connector 22.
In the related-art relay connector disclosed in JP-A-2008-171801, a distance between the core conductor 22c and the board rest part 26b is enlarged by the relative movement between the main block 20 and the GND block 26, whereby the board can be inserted between the core conductor 22c and the board rest part 26b, and the core conductor 22c is moved close to the board rest part 26b by the relative movement, whereby the board can be clamped between the core conductor 22c and the board rest part 26b. The core conductor 22c of the coaxial connector 22 is brought into contact with a terminal electrode provided on the surface of the board, and electrically connected thereto. Moreover, a GND electrode provided on aback surface of the board is electrically connected to the shell GND 22a of the coaxial connector 22 from the GND block 26 having the board rest part 26b, by way of the main block 20. In this manner, electrical connection between the board and the coaxial connector 22 can be easily performed. Moreover, by enlarging the distance between the core conductor 22c and the board rest part 26b by the relative movement, the board which has been inserted between the core conductor 22c and the board rest part 26b can be easily removed. In addition, by pressing the operating member 30 against elasticity of the elastic members 34, 34 to be moved toward the main block 20, the board rest part 26b of the GND block 26 which is coupled to the operating member 30 by means of the coupling members 38, 38 relatively moves to be separated from the core conductor 22c, and the board can be inserted between the core conductor 22c and the board rest part 26b which have been separated. When the pressure on the operating member is released, it is possible to clamp the board between the core conductor 22c and the board rest part 26b with the elasticity.
The related-art relay connector disclosed in JP-A-2008-171801 is excellent in that electrical connection between the board and the coaxial connector 22 can be easily performed. However, it is desired that posture of the GND block 26 is more stabilized with respect to the main block 20. Although the posture of the GND block 26 is restricted by detachably inserting the guide pins 24, 24 into the guide holes 26a, 26a, the posture is likely to become unstable because of slight clearances which are required for smooth insertion and smooth withdrawal of the guide pins. Moreover, although the coupling members 38, 38 are coupled to the GND block 26 by means of the coupling pins 36, 36, the coupling members 38, 38 can relatively rotate with respect to the GND block 26 around the coupling pins 36, 36, and hence, do not function for stabilizing the posture of the GND block 26. For these reasons, the posture of the GND block 26 is not stabilized with respect to the main block 20, and constant electrical connection between the main block 20 and the GND block 26 cannot be necessarily obtained. In case where the posture of the GND block 26 is unstable, the contact between the board rest part 26b and the GND electrode on the back surface of the board is also varied, which will make a path of the electrical connection from the GND electrode on the board to the main block 20 unstable, and there is such a drawback in that electrical performance of the path may be varied at every time when the performance is evaluated.